Flow Cytometry and cell sorting are integral and essential components of modern biomedical research. These techniques allow for the rapid identification of individual cells within a mixed population based on such properties as cell surface antigen expression, cell cycle status, cell signaling, or fluorescence- tagged transgenes. Furthermore, once cell populations are identified they can be isolated into discreet populations via cell sorting. Core E, Flow Cytometry, is operated under a cooperative arrangement with the University of Colorado Cancer Center Flow Cytometry Shared Resource (CC-FCSR).This state-of- the-art facility provides two instruments capable of high speed cell sorting based on up to 14 color parameters. Additionally, the CC-FCSR provides four flow cytometer analysis machines capable of up to 10- color analysis, two ViCell cell counters, and a Luminex Magpix system for multiplexed bead array analysis of cytokines, chemokines, and cell signaling proteins. The CC-FCSR personnel provide a consultation service for analysis and cell sorting strategies, cell preparation, and assay trouble-shooting. The Flow Cytometry Core has been used extensively by investigators involved in skin disease. The core is capable of identifying and isolating various skin cell subpopulations, such as keratinocytes and keratinocyte stem cell populations, as well as isolating normal and skin tumor stem cells from tissues or cell cultures for further in vitro and in vivo analysis. Additionally, investigators are able to identify, isolate, and further assess phenotype-specific T cell or other immune cell populations associated with various skin pathologies. Flow Cytometry Core center support insures that investigators of the UCAMC Skin Diseases Research Core have full access to all services provided by the CC-FCSR at a subsidized rate.